Two workers must slide a crate designed to be pushed and pulled at the same time
ID: 1283325 • Letter: T
Question
Two workers must slide a crate designed to be pushed and pulled at the same time as shown in the figure below. Joe can always exert twice as much force as Paul, and Paul can exert 151 N of force. The crate has a mass m = 40 kg, the angle ? = 25
Two workers must slide a crate designed to be pushed and pulled at the same time as shown in the figure below. Joe can always exert twice as much force as Paul, and Paul can exert 151 N of force. The crate has a mass m = 40 kg, the angle ? = 25° and the coefficient of kinetic friction between the floor and crate is 0.53. If we want to move the crate as fast as possible, is it better to have Paul push and Joe pull, or vice-versa? Calculate the (horizontal) acceleration for both cases to find out.Explanation / Answer
I have included and subtracted friction. Just that I don't know the formula for it.
Ff=Fn*miu(k)
miu of kinetic friction is given, Fn is unknown and I am not sure how to express it.
One option is Fn - m*g*sin_20 + Fpull_sin_20+ Fpush_sin_20 = 0 the other option is Fn=mgsin20.
Regarding the acceleration on the x axis:
If the angle is 20 in both cases would this be a right formula then? I am not sure what it is that quantifies the difference that I intuitively understand should give me a greater magnitude when the stronger guy pulls.
when paul pushes:
a(x)=(fpush_paul*cos20+fpull_joe*cos20 -Ffriction) / mass
when joe pushes:
a(x)=(fpush_joe*cos20+f pull_paul*cos20 - Ffriction) / mass
Please advise.
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